With the development of railroad cars, new-type and high speed motor train units are emerged continuously, which imposes stricter requirements on installation and connectors of the motor train units, the connectors must ensure needles against being disconnected during high speed running of the vehicle and a reliable contact of the needles.
The conventional self-locking type and interlocking type insertion needle disconnection prevention methods fail to address the issue of needle disconnection when the motor train units are in a high speed running condition and in complex road conditions. Furthermore, in the self-locking and interlocking disconnection prevention methods, when the needle is withdrawn, a special tool is required to separate a socket from a plug, which tends to cause a self-locking spring or an interlocking spring to be damaged and lose the elasticity, and therefore cannot be used repeatedly. As shown in FIG. 1 which shows a conventional train connector in a state of disconnection, the connector includes a socket 1 and a plug 2. The socket 1 includes an insertion needle 101 and an insulator 102. The insertion needle 101 is fixed by a retaining slot 103 and a retaining spring arranged in the retaining slot 103. The plug 2 includes an insertion needle 201 and an insulator 202. The insertion needle 201 is fixed by a retaining slot 203 and a retaining spring 204 arranged in the retaining slot 203. In use, the insertion needle 201 of the plug 2 is inserted into the insertion needle 101 of the socket 1 to achieve connection between the plug and the socket. Such a connector is likely to generate needle disconnection during use due to the high speed running of the train, thus may adversely affect the use of the connector.